The present invention relates to expandable watercraft and, more particularly, to a watercraft system expandable from a mono-hull to a multi-hull and able to be contracted back to the mono-hull so as to take advantage of both types of hull designs depending on the boating conditions.
A boat floats because it displaces a greater weight of water than its own weight. When a boat is sitting still or moving slowly, the hull is “in displacement mode.” That is, all of the upward forces keeping it on top of the water come from flotation obtained by displacing water. Increase the boat's speed beyond a certain point with certain hulls and the hull rises up and skims along on top of the water. This is called “planing.” As a result, generally speaking, a hull can be described as a displacement hull or a planing hull.
The displacement hull is typically restricted to relatively slow speeds but is extremely efficient to run. In comparison, the planing hull is designed to achieve high speeds on the water by transitioning onto a plane easily. Planing hulls may include flat bottom surfaces from amidships aft (from the middle to the back of the bottom) and a flat transom (back of the hull). The transom may meet the bottom at a sharp angle.
Boats come in two broad categories: mono-hull (or single hull) and multi-hull. Mono-hull boats typically have a flat transom stern and a pointed bow for facilitating planing. Multi-hull boats have two or more hulls joined by a bridge deck or other structure. Multi-hull boats provide a good rough-water ride as they can take on big waves with a stable platform. Also, wider boats feel more stable, which makes them popular for dockside entertaining or angling. Multi-hull boats suffer, however, from the disadvantage of being too wide for conventional marina docks and convenient transport over land.
Narrower, mono-hull boats more readily offer the planing hull, the need for speed, and the need to operate in tight quarters. Plus, it can take more fuel to move a wide boat at a given speed than a narrow hull of similar length. Single narrow hulls, however, have trouble handling heavy weather and cannot take on big waves at high speeds, but must reduce to displacement mode. In fact, if the boating conditions are sufficiently adverse, skippers of such narrow, mono-hull boats are advised to forget their intended destination and bring the bow around into the wind and waves using just enough power to make bare steerage.
As can be seen, there is a need for a watercraft system extendable from a mono-hull to a multi-hull and able to be contracted back to the mono-hull so as to take advantage of both types of hull designs depending on the boating conditions.
An extendable hull system movable between mono-hull and multi-hull offers advantages, yet, also presents challenges. For example, conventional watercraft weather screens (for sun and rain protection) do not contemplate being employed on expandable watercraft, and as a result their framework is rigid and non-adjustable; moreover, such weather screens would not provide efficient coverage for expandable watercraft, as they would not be able to adjustably expand along with such watercraft.
Therefore there is a need for a weather screen assembly that can remotely expand to cover the entire length of an expanded watercraft as well as provide efficient coverage when the expandable watercraft is in a contracted configuration. Moreover, the weather screen assembly could advantageously expand out and hang over the edge of each side of any watercraft to provide for the roll off of rain without getting in the watercraft. Also, screens can be attached to the weather screen assembly to keep bugs outside the boat, and video and audio output device could be removably affixed to the weather screen assembly.
Furthermore, expandable watercraft may suggest the need to further expand the walking space beyond its expanded configuration because of the stability on the water it affords. Therefore there is a need for further expanding the walking space by providing a railing system that may be movable from a locked configuration to a deployed configuration, providing an additional walking surface generally flush with the expandable decking in the expanded or contracted configuration. In the locked configuration, the railing system may be locked generally perpendicular to the decking so as to provide protection to crew and deck furniture from going overboard.
As can also be seen, there is a need for an expandable watercraft system to provide solutions to the challenges presented by being movable between multi-hull and mono-hull configurations.